Thread Cutting Using The Top Slide; Cutting Left Threads; Accessories For Lathe Pd 250/E; Installing The Centre Lathe - Proxxon PD 250/E Manual De Instrucciones

Important
The automatic feed must remain switched on until completion
of the thread. Disengaging between individual steps
renders further work impossible.
Only switch over the motor switch once the lathe chuck has
come to a complete standstill. Switching over immediately
increases wear and reduces the service life of the motor.
6. Move back the turning tool slightly with the cross-slide.
7. Move the support back to the output position. To do so,
switch over the turning direction of the main spindle.
8. Advance the turning tool and repeat the steps described
above until the required thread depth is reached.

Thread cutting using the top slide

A perfect, good-quality thread can only be cut by using the top
slide (accessories).
Advancing the thread tool is performed using the cross-slide as
described above.
However, this causes the top slide to shift by 0.025 mm to the
left and the same distance to the right.
The chip in the thread is therefore always only removed from
one side.
Once the full thread depth has been reached, a final full cut is
made by advancing slightly.

Cutting left threads

To cut left threads, the intermediate gear 1 (Fig. 21) must be
installed between "Z -Z " and the leadscrew gear "L1".
1 2
In doing so, the turning direction of the leadscrew is reversed.
The support runs from right to left when the chuck is turning
clockwise.
Installation and operation are as described above.

Accessories for Lathe PD 250/E

The following accessories are not included in the standard
equipment.
Installing the centre lathe (No. 24014)
Longer work pieces are clamped between the brad points of
the main spindle and tailstock.
The work piece must have a centre bore on both faces.
An exact cylindrical work piece is only achieved if the points
align in the horizontal position.
1. Remove three fastening screws from the three-jaw chuck
and remove chuck.
2. Thoroughly clean the fit for the driving disc and centre and
its fit in the main spindle.
Note:
Note:
3. Insert the centre 4 (Fig. 22) in the fit 1 of the main spindle.
4. Fit the driving disc 2 and fasten with three screws 3.
5. On the left side, insert driving pin in one of the three long
holes on the driving disc and the centre in the centre bore.
6. Push the lathe carrier 1 (Fig. 23) onto the work piece (driving
pin outwards) and tighten the fastening screw 2.
7. On the right side, attach the work piece using the tailstock
and fixed or rotating centre.
Important
When using a centre fixed to the tailstock, regular lubrication
of the centre and centre bore is necessary to prevent the tem-
per from loosening.

Removing the centre

8. Guide a suitable aluminium or brass rod through the main
spindle from left to right.
9. Hold the centre and release by lightly tapping the rod.
Four-jaw chuck (No. 24036)
Round, oval, square and irregularly shaped work pieces can be
clamped as it is possible to adjust the jaws individually.
Centric or eccentric clamping is possible.
Unlike the three-jaw chuck, centring of the work piece must be
performed manually.
Important
Remove mains plug.
1. Detach the three-jaw chuck and attach the four-jaw chuck.
2. Open the four jaws, clean the contact faces and clamp the
work piece lightly according to visual estimation.
3. Move the support and turning tool onto the plane surface of
the work piece.
4. Turn the chuck by hand to establish symmetrical deviations.
5. Adjust by opening one of the jaws and re-set the opposite
jaw accordingly.
6. Tighten all four jaws evenly, alternating crosswise.
Important
In the normal clamping jaw position, only work pieces with an
edge of up to max. 30 mm long can be clamped. The maximum
length is 80 mm in the reverse position.
Larger work pieces are not securely held. Danger of accident.
Note:
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